My '89 300E is a dream car. I have put about 35,000 KM (approx. 21, 000 miles) on it since I bought it. In that time, all I have had to do was replace a lower control arm bushing ($150) and the front oil seals ($200). The AC works but is low on freon. Since I rarely use it, I think I will put this one off for a while. From what I have heard, the climate control system for this car is a bit of a nightmare and is $$$ to fix (especially if the evaporator goes!). At my last check-up, everything was A-OK, but I am being told my belt tensioner shock is noisy. It seems this is a common problem (Bill's post)?
Regular maintenance is not expensive and the car handles and drives like a dream. The only thing I didn't like about the car was very minor - the horrible Becker radio which I have since replaced with an Alpine.
Good luck shopping around!
'71 250 (retired)
'77 280E 210 K
'89 300E 205 K